Apple’s 2010 Music Event is over, and as expected, it brought new iPod models, a new Apple TV, and a new version of iTunes—plus information on iOS versions 4.1 and 4.2. Here’s a quick summary of the key announcements. Fourth-generation iPod shuffle: $49 (2GB). After the huge flop of the third-generation shuffle, Apple has switched the body completely, with a new design that preserves all of the buttons on the face like the iPod shuffle…